Testing of an Improved Cumulus Parameterization in the NMC Global Model

兰德尔博士开发了一种新的积云参数化方法 它以研究的方式运行， 科罗拉多州立大学的模特。 早期结果与此 参数化是很有希望的。 在这个奖项下， 参数化将在一个运行环境中进行测试， 国家气象中心（NMC）的全球预报模型。 积云在数值模式中的正确表示是 对改善天气预报至关重要。 积云是 在释放潜热方面很重要， 在发展中发挥着重要作用， 雷暴和热带气旋的演变。 新计划有许多特点，使其对 既有实际的原因，也有科学的原因。 与其前身不同， Arakawa-Schubert参数化，此版本允许穿透 在模型中的任何高度形成积云。 它还允许 形成浅积云对流下沉气流。 因此，新方案使数值模型更接近于 在大自然中观察。 从计算上看，新方案似乎是 在简单性和速度方面是上级的。 新计划的预测将与过去的预测进行比较。 与国家气象中心目前的积云方案。 主要研究者 希望证明他的鲁棒性和模型独立性 参数化 该项目得到了NSF-NMC联合项目的支持。 数值天气预报程序。

Dr. Randall has developed a new cumulus cloud parameterization that has been run in a research mode with the general circulation model at Colorado State University. Early results with this parameterization are quite promising. Under this award, the parameterization will be tested in an operational environment using the National Meteorological Center's (NMC) global forecast model. Proper representation of cumulus clouds in numerical models is essential for improving weather prediction. Cumulus clouds are important in releasing latent heat which drives the atmospheric circulation as well as playing a major role in the development and evolution of thunderstorms and tropical cyclones. The new scheme has many features which make it attractive for both practical and scientific reasons. Unlike its predecessor, the Arakawa-Schubert parameterization, this version allows penetrative cumulus clouds to form at any level in the model. It also allows for the formation of shallow cumulus cloud convective downdrafts. The new scheme thus brings the numerical model closer to what is observed in nature. Computationally, the new scheme appears to be superior in terms of simplicity and speed. Forecasts with the new scheme will be compared with those made with NMC's current cumulus scheme. The principal investigator hopes to demonstrate the robustness and model independence of his parameterization. This project is being supported under the NSF-NMC Joint Program in Numerical Weather Prediction.